Thermoplastic resins have lower specific gravity than glass or metals, and also can have excellent mechanical properties such as moldability, impact resistance, and the like. Plastic products prepared using such thermoplastic resins have rapidly replaced glass and metals in various fields including electric and electronic products, automobile parts, etc.
In recent years, there has been an increasing demand for products having a low gloss appearance. Gloss-less paint has been applied to the surface of plastic products to provide a low gloss surface. There are, however, environmental concerns associated with the same. Accordingly, there has been an increased demand for low-gloss resins.
To realize a low-gloss effect without using a gloss-less paint, a method of realizing a low-gloss effect by adjusting surface smoothness of a resin in a wavelength range greater than a visible-ray region to scatter incident light has been widely used. For example, there are methods using a large-sized rubbery polymer or using a matting agent as an additive. However, such methods can have problems, such as poor low-gloss effect or degraded heat resistance and impact resistance. As another method, a method of graft-polymerizing a monomer such as ethylene-unsaturated carboxylic acid into a resin has been used. This method can provide various good physical properties, but can also rapidly degrade heat resistance.
U.S. Pat. No. 4,460,742 discloses a low-gloss resin composition in which a cross-linked copolymer is used. Such a resin composition has a matte appearance when large-sized rubber particles or a matting agent is added. However, the resin composition can require an excessive amount of the matting agent, which can degrade impact strength and temperature resistance.